Single-use containers for liquids have been used in the most varied shapes and sizes for a long time. Beverage cans made of light metal with a lid that is equipped with a lifting tab closure are particularly common. According to a first embodiment, the area or portion of the lid that forms the outlet opening is pushed into the can when the lever or lifting tab is operated and remains captively connected to the can top. According to another embodiment, this tab is removed together with the area or portion of the lid that forms the outlet opening when the lifting tab is operated. Such closing systems are described, for example, in WO 97/030902, DE 100 18 685 C2, U.S. Pat. No. 4,148,410, EP 564 725 A1, WO 2005/056400 A1, and GB 2 379 917 A.
The lever or lifting tab on such containers can be rotated around a fastening means, frequently a rivet, that is connected to the lid surface in a central position. The lifting tab overlaps at its first end an area of the lid surface that covers the outlet opening. The outlet opening is opened when the lifting tab is lifted at the opposite second end and the first end exerts a force on said area. Since the first end of the lifting tab only has a minor overlap with the area of the lid surface that covers the outlet opening and that is often defined by a tear profile, it is typically necessary to open the can with an ideally aligned lifting tab, i.e., from its opening position. Otherwise, the lifting tab may break off or bend, and the beverage can can no longer be opened.
To solve this problem, U.S. Pat. No. 3,453,877 proposed to provide an elevation in the lid surface between the rivet for the lifting tab and the area of the outlet opening that is to engage a corresponding hole in the lifting tab. GB 1 106 828 proposes the same approach. Small apertures in the region of the lifting tab are meant to interact with corresponding protrusions for this purpose.
JP 07 275976 A also provides a protrusion next to the rivet in the lid surface that is to engage a corresponding hole in the lifting tab.
According to DE 10 300 914 A1, turning of the lifting tab is prevented by strip-shaped protrusions from the lid surface in the form of beads, which are intended to limit the edge of the opening tab and hold it when not in use.
GB 1 534 703 discloses a lifting tab having a pull ring that is prevented from rotating freely about the rivet by two protrusions attached to the inner side of this ring. The device for holding the lifting tab in position according to GB 1 422 648 merely differs from that disclosed in GB 1 534 703 in that the protrusions are not disposed on the inner edge but on the outer edge of the lifting tab to help prevent its rotation out of position.
According to DE 60 2005 002 878 T2, twisting of the lifting or opening tab can only be effectively prevented by attaching a removable adhesive tape, which at the same time covers a ventilation hole.
According to DE 28 42 449, a protrusion of the opening tab is pressed against the lid surface for pretensioning. This is to prevent a pivoting movement of the opening tab.
JP 8 053 131 A proposes a pin that projects from a can lid and is to help keep a lifting tab in its position through an opening. U.S. Pre-Grant Publication No. 2002/0088804 A1 discloses a comparable solution, wherein a so-called support is used for additional locking to prevent the lifting tab from rotating.
JP 9 226762 A proposes a protrusion from the lid surface that is to engage a corresponding hole in the tongue of the lifting tab for locking the lifting tab in place. WO 98/33715 A1 proposes a similar solution.
JP 2006 176142 A finally proposes a rivet with projections to prevent it from rotating.
The lid variants known from prior art all have disadvantages and leave room for improvement. For example, users or customers can still operate the tabs incorrectly.